1. Look "Tiny Cooling Fan" style.
2. Look at the "Tiny Cooling Fan" Appearance: The appearance in addition to beautiful, but also paint and chrome is smooth, straight, no wrinkles, blade rotation should be smooth.
3. measure "Tiny Cooling Fan" performance: see whether the key is turned Lee winded, shaking his head and timer test whether spiritual, accurate control, there is no difference in the wind, smooth blades, no noise, no leakage, temperature normal.